Publication Date:
2014-10-05
Description:
The structures of the 1:1 co-crystalline adduct C8H6BrN3S·C7H5NO4, (I), and the salt C8H7BrN3S+·C7H3N2O7−, (II), obtained from the interaction of 5-(4-bromophenyl)-1,3,4-thiadiazol-2-amine with 4-nitrobenzoic acid and 3,5-dinitrosalicylic acid, respectively, have been determined. The primary inter-species association in both (I) and (II) is through duplex R22(8) (N—H...O/O—H...O) or (N—H...O/N—H...O) hydrogen bonds, respectively, giving heterodimers. In (II), these are close to planar [the dihedral angles between the thiadiazole ring and the two phenyl rings are 2.1 (3) (intra) and 9.8 (2)° (inter)], while in (I) these angles are 22.11 (15) and 26.08 (18)°, respectively. In the crystal of (I), the heterodimers are extended into a chain along b through an amine N—H...Nthiadiazole hydrogen bond but in (II), a centrosymmetric cyclic heterotetramer structure is generated through N—H...O hydrogen bonds to phenol and nitro O-atom acceptors and features, together with the primary R22(8) interaction, conjoined R46(12), R21(6) and S(6) ring motifs. Also present in (I) are π–π interactions between thiadiazole rings [minimum ring-centroid separation = 3.4624 (16) Å], as well as short Br...Onitro interactions in both (I) and (II) [3.296 (3) and 3.104 (3) Å, respectively].
Keywords:
5-substituted-2-amino-1,3,4-thiadiazoles4-nitrobenzoic acid3,5-dinitrosalicylic acidproton transfermolecular adductsco-crystalshydrogen bondingπ–π interactionscrystal structure
Electronic ISSN:
1600-5368
Topics:
Chemistry and Pharmacology
,
Geosciences
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